Drop-hammer.



B.v & J. BRETT.

DROP HAMMBR. APPLIOATION FILED MAR. B, 1910.

Patented Novl 8, 1910.

2 SHEETS-SEEET-l.

THE "amers PETERS cm, wAsHnvcmN, n. c.

B. & J. BRETT.

l DROP HAMMER. APPLIOATION FILED MAE. 8, 1910.

Patented Nov.8, 1910.

5. i. ,W 6 2 f .4 2 2 M 2 M w 0.v

E M m o E .o M25. 2. 2 4v 2 2 ...o 2. g. 2 m... W .5 i

Vla; d rei' 0 0 7222,32 "c Z nl: Nakms PETERS co., wAsylNa-ron. n, c.

Zzye/z fares Sai BERNARD BRETT AND JOI-IN BRETT, OF COVENTRY, ENGLAND.

DROP-HAMMER.

Specification of Letters Patent.

:Patented Nov. s, 1910.

Application led March 8, 1910. Serial No. 548,068.

To all whom it may concern.'

Be it known that we, BERNARD BRETT and J oHN BRETT, subjects of the King of Great Britain, residing at 7 Barrs Hill, Coventry, Warwickshire, England, have invented certain new and useful Improvements in Drop'- Hammers, of which the following is a specification.

This invention relates to improvements in drop hammers, and has reference to the lifting mechanism of such hammers, by which a much more certain and sensitive action is obtained than hitherto.

Briefly, our invention consists of a novel form and arrangement of friction lifting pulleys and friction block arms, which are actuated by an improved lever device. Such an arrangement may be of a double or single character, that is to say, for hammers of a heavy kind the double type may be used, while for lighter hammers, the single type are suiiicient.

In order to more clearly explain this our invention we have appended hereunto illustrative sheets of drawings, upon which are gures and numbers of reference, similar numbers referring throughout the several views to the same thing or.k part, and in which Figure 1 is a front view in elevation of a drop hammer constructed according to this our invention, and showing the clutch like mechanism as of the multiple or double driven type. Fig. 2 is an enlarged sectional view of the invention. Fig. 3 isa front view, and Fig. 4 an end view of the mechanism as arranged for the single clutch form. Figs. 5 to 9 inclusive show details and modifications of the mechanism.

Referring now more particularly to Figs. 1 and 2, the shaft 13 is driven by any suitable means in a continuously running manner. Upon this shaft is mounted the idle pulley 14 which supports the lifting rope or band 15. 16, 16, are pulleys which are placed one on each side of the free revoluble or idle pulley 14, and which are keyed to the shaft 13. In the periphery of these pulleys is formed the somewhat V shaped groove 17. 18, 18, are the lifting arms which are made slidable in a radial direction, that is to say, their outer ends are capable of being moved nearer to or farther from the center of the shaft 13. The means of permitting this movement may be varied, but that shown consists of an oblong hole 19 being formed in the arm (see Fig. 5) which slidingly fits the` shaft 13. The two outer ends of these radial arms 18, 18, are connected together by the cross rod 20. To the center of this cross rod the end of the lifting rope or band 15 is secured, and upon each side of the same the friction blocks 21 are rigidly secured, which levers 24, whose one end is connected to they arms 18 at 25, above and below the shaft 13. The other end of these levers 24, is fitted with a roller 26 which is acted upon by the slidable cam block 27, which latter is mounted freely on the shaft. formed with oppositely located tapered or inclined surfaces 27 i and 27b which are disposed parallel with eaoh other. These blocks are slidingly operated by means of the forked levers 28, whose one end (or a roller thereon) engages in the usual manner with the circumferential groove 29 in the block 27. These fork levers are further connected to each other by the connecting rod These blocks are 30, so as to actsimultaneously, and again further connected to the primary operating rod 31 by means of the short arm 28a. The rod 31 is carried to any convenient position, or form, for the operator. Its action will therefore be understood as follows z-As shown in Fig. 2 the blocks 21 are held free of the grooves 17 and therefore the arms 18 are stationary. When however the rod 31 is drawn downward, the cam blocks 27 are forced inward, and in so doing the arms 18 are drawn downward so that the blocks 21 are wedged sufficiently tight into the grooves of the revolving pulleys 16, as to cause them to forcibly carry with them the said blocks 21, and together with them the rope or band 15, and thus to raise the hammer block 32. Immediately however that the pressure from the rod 31 is released the hammer falls, and the cross rod 20 is brought back to zero, ready for a repeat movement. Lest in such return movement it should happen that the blocks 21 should not readily free themselves from the grooves 17, the cam blocks are made (as described) with the oppositely parallel acting surfaces 27a and 27 b so as to insure a positive movement in both directions of the arms 18.

Referring now more particularly to Figs. 3 and 4, it will be seen that the driving clutch mechanism may be used in the single clutch character, when required only for light hammers. In this case the boss of the arm 18@l is furnished with a central round hole to freely fit the shaft 13, and therefore is not slidable but used only that its outer end 18b may serve as a fulcrum to the cross rod lever 20a (which in this case is substituted for the cross rod 20 aforesaid), its other end being connected up to the slidable arm 18 as before. The operation from the rod 31 in this case will be clearly understood from the description already given.

When a single pulley 16 only is used, the rope 15 may lie upon the bottom of the groove 17, but here again we provide that such a surface should not frictionally rub the underside of the lifting band. This may be done for instance, as shown in Figs. 8 and 9, in which revoluble rollers 33 are mounted on the pulley 16 between it and the idle pulley ring 34 in such a Vmanner that the rope is carried on such ring. It will also be readily seen that if desired the said singly used pulley 16, as immediately above referred to, may be of the solid kind shown in Fig. 2, and an idle pulley 14 placed at its one side between it and the non-slidable arm 18a on which the rope or band may rest.

We are aware that it has already been proposed to operate such hammers by means of a radial lifting arm being made to friction ally cause a brake like block to bear upon the flat surface of a revolving pulley, but in such cases the lifting band has rested upon the moving pulley, and has caused a wearing action upon such band. y

What we claim as vour`invention and desire to secure by Letters Patent is 1. In lifting mechanism for drop hammers, a shaft rotatable in one direction, a hoisting pulley mounted onthe shaft for rotation therewith, a hammer block, a cable carrying -the hammer block, a pulley freely rotatable about the shaft as a center and over which the cable is trained, a cross piece to which the end of the cable is attached, the cross piece having means to frictionally engage the hoisting pulley and being movable to establish or disestablish such engagement, and arms to which the cross piece isconnected, thearms surrounding the shaft.

2.- In lift-ing mechanism for drop hammers, a shaft rotatable in one direction, a pair of hoisting pulleys mounted on the shaft for rotation therewith, a freely revoluble pulley arranged between thefhoisting pulleys, a hammer block, a cable carrying the hammer block and trained over the freely revoluble pulley, a cross piece to which the end of the cable is attached, the cross piece having means to frictionally en gage the hoisting lpulleys and being movable to establish or disestablish such engagement, arms surrounding the shaft, radially movable with respect thereto, and connected to the cross piece, the movement of the latter aforesaid being consequent to the movement of the arms, and means for producing the movement of the arms in either direction.

In testimony whereof we have hereunto set our hands in the presence of two subscribing witnesses.

BERNARD BRETT. JOHN BRETT. 

